Process of minimizing the production of foam in steam generators



Patented Sept. 21, 1948 STATES PROCESS OF MINIMIZING THE PRODUC- TION FFOAM IN STEAM GENERATORS Robert W. Kell, Oak Park, 111., assignor toNation- I al Aluminate Corporation, Chicago, 111., a corporation ofDelaware No Drawing. Application November 3, 1943, Serial No. 508,864

uids.

One of the objects of the present invention is to provide a liquidsuitable for the generation of steam in steam generators, and comprisingwater containing dissolved therein a very small amount of sulfonamide,whereby, when such water is heated to the boiling point in a steamboiler or other generator, being thereby evapo-- rated, theconcentration of solids therein will not bring about excessive foamingor priming resulting therefrom. The compounds incorporated in the waterare substantially non-volatile with steam and are stable, so that theywill be retained by the water, and neither they nor their decompositionproducts will appear in the steam or in the condensate thereof.

It is well known in the operation of steam boilers, such as in electricpower'plants, railroad lo-' comotives, and the like, or in evaporators,that the water therein, even though initially it shows very littletendency to foam, will, when the amount of total solids thereinapproaches a relatively high concentration, develop a Very decidedtendency to foam. When this occurs, considerable quantities-of Water arephysically carried out of the boilers or evaporators with the steam,thus appearing in the steam lines and in the eventual condensate. Suchpriming has many disadvantages because it tends to contaminate the steamlines, to plug or corrode the valves, and under serious conditions mayeven impair the cylinders tallow, and the like. While these fattymaterials have some small degree of efficiency, they are,

on the other hand, quite deficient in that they introduce newdifficulties which, in some instances, are worse than the conditionsthey are intended to cure, In the first place, these fatty acids orglycerides are unstable under the conditions existing in the boilers,particularly as the pressure and temperature increase, thehightemperatures leading to rapid decomposition of the glycerides,which, if anything, will tend to increase the foaming and primingdiificulties. Furthermore, in many instancescertain of the decompositionproducts thus produced, or sometimes even the materials themselves, havea definite volatility with steam, and will therefore 5 Claims. (Cl.252-321) steam-distil out of the boilers, thus appearin in the steam andin the condensate. This, of course, is also very undesirable.Furthermore, such types of antiioaming agents usually have to beemployed in relatively large quantities, adding not only to the expensebut also to the inconvenience of operating the steam generators; andthose which have a tendency to decompose do so quite rapidly, and hencetheir efiectiveness is of short duration, which therefore necessitatesthe continual charging into the boilers or other steam generators ofrelatively large amounts of these older antifoaming agents. Moreover,such antifoaming agents are difiicult to use because the amounts inwhichthey are efiicacious are v ry critical, and any overdosage usuallyaggravates the difficulty instead of curing it.

Applicant has now discovered, however, that there is a series ofcompounds, which may be broadly designated as sulfonamides, which are ofa high order of emciency when used as antifoaming and antipriming agentsin steam generators. For application in certain foaming problems, thesesulfonamides should possess certain limiting characteristics as regardsmolecular size as hereinafter more fully described.

Fundamentally speaking, the compounds involved in the practice of thepresent invention can be illustrated by the following structuralformula:

inv which X is the hydrocarbon radical of a sulfonic acid from the groupconsisting of aliphatic and aromatic sulfonic acids-i. e., X-SOz is thesulfonyl radical of an aliphatic or aromatic sulfonic acid; Y is theresidue of an amine from the group consisting of the alkylene amines,including the alkylenediamines and polyalkylene polyamines, and thearomatic polyamines; and Z is a member of the group consisting ofhydrogen, an

'acyl radical, and the sulfonyl radicals of aliphatic and aromaticsulfonic acids. Where Z is a sulfonyl radical, it may be identical withor different from the sulfonyl radical X--SO2.

The sulfonamides which I have found to be most useful in reduction orelimination of foaming are the disulfonamides of long chain aliphaticsulfonic acids. For application in certain foaming problems, thehydrocarbon radical, i. e., X in the above probable structural formula,should contain at least about 12, and preferably 16 or more, carbonatoms, although for other purposes 3 compounds in which the radical Xcontains fewer carbon atoms may be satisfactory. Also of value arecertain sulfonamides of dlbasic sulfonic acids, such as decane1,10-disulfonic acid.

The preparation of a number of suitable antifoaming agents is describedhereinbelow, and while the examples disclose some of the satisfactorypreparative procedures, in most cases the same product may be obtainedby more than one method.

The most-used method of preparation involved the use of a sulfonylchloride with a nearly theoretical amount of an amine. In thepreparation of the dlsulfonamides, two mols of the desired sulfonyllChlOIldB were reacted with 1 mol of an amine which might be apolyalkylene polyamine, such as diethylene triamine, triethylenetetramine, tetraethylene pentamine, and analogous amines in which one ormore of the alkylene groups are propylene, butylene, and higher alkylenegroups, or an alkylene di amine in which the alkylene group mightcontain 1, 2, 3 or more carbon atoms, or an aromatic polyamine such as111-, or p-pheny lene diamine, benzidine, diamino-benzophenone,e-amino-diphenylamine, diamino diphenyl ether, \and other like amines.After mixing the selected sulfonyl chloride and amine, heat is appliedto effect the desired reaction.

Unsymmetrical sulfonarnides were prepared by reacting an amine, suitablya polyamine, with two d ifierent sulfonic acid chlorides or by otherprocedures.

Particularly eifi-cient antifoaming agents falling within the scope ofthe present invention include the condensation products made from:

(1) cetyl sulfonyl chloride and diethylene-triamine;

(2) lauryl sulfonyl chloride with triethylenetetramine;

(3) a sulfonyl chloride (formed by the reaction of a sulfonated longchain hydrocarbon, having 13 to 18 carbon atoms, the sodium salt ofwhich is sold under the name of M. P. 189 by E. I. du Pont de Nemours &Company, with P015) and tniethyi enetetramine;

(4.) the sulfonyl chloride prepared from mahogany soap (the sodium saltof the oil-soluble petroleum sludge sulfonic acids), andtriethylenetetramine;

(5) cetyl sulfonyl chloride and ethylenediamine;

(6) cetyl sulfonyl chloride and benzidine;

('7) cetyl sulfonyl chloride and hydroxy-ethylethylenediamine;

(8) cetyl sulfonyl chloride and ammonium hydroxide and thenformaldehyde;

(9) cetyl sulfonyl chloride and ethylene-diamine and subsequently acetylchloride;

(10) cetyl sulfonyl chloride and hydrazine and subsequentlydichloroa/cetone;

(11) cetyl sulfonyl chloride, diethylene-triarn ine, and benzenesulfonyl chloride;

(12) sulfonyl chloride prepared from a detergent composition known (asGeneral Aniline & Film Corp. S. A. 151 (a sodium salt of a carboxylatedsulfonic acid) and d-iethylenetriamine; and

(13) the reaction product of oleic acid with chlorosulfonic acid andsubsequently with diethylene-triamine.

Other materials of value include the following: dilauryl sulfonamide ofdiethylenetriamine; dicetyl sulfona'rnide of triethyilenetetramine;

dicetyl sulfonamide of 1,3-d iamino-propanol-Z;

dicetyl sulfonamide of o-phenylenediamine;

dicetyl sulfonamide of hydrazine;

dicetyl sulfonamlde of propylenediamine;

monocetyl sulfonamide of acetyl diethylenetria-mine;

dicetyl sulfonamide o'f methylenediamine;

reaction product of mono-oleyl ethylenediamine and the sulfonyl chlorideof S. A. 151;

reaction product of sulfonated oleic acid and diethylenetriamine.

The number of different compounds which can be prepared is quitenumerous, and while a [large number of examples are given hereinafter,it is to be understood that the invention is not to be limited to thosespecifically described, nor to the species to which the more limited aredirected. The examples are as follows:

Example 1.--Cetyl sulfonic acid was neutralized to form a sodium saltand treated with PCi5 to form cetyl sulfonyl chloride. 18.3 parts byweight of cetyl sulfonyl chloride so prepared was mixed with 3 parts byweight of diethylenetriamine and the mixture heated at to C. for threehours with stirring. The product so formed was a highly efiectlve agentfor retarding foaming in boilers.

By a similar procedure, dicetyl sulfonamides of triethy lenetetramine,hydrazine, propylenediamine and 1,3-diamino-propanol-2 were prepared.These disulfonamides likewise were effective antifoaming agents.

Example 2.-6 parts of lauryl sulfonyl chloride were added to 1.9 partsof triethylenetetramine, and the mixture was heated at 150 to 160 C. andmaintained at that temperature for two hours. The resulting product wasan excellent antifoaming agent.

By the same procedure, the dilauryl sulfonamide of diethylenetriaminewas obtainedand found to be an antifoaming agent.

Example 3.14 parts of a detergent material, presumably a sodiumsulfonate, known as do. Ponts M. P. 189 was mixed with 10 parts of P015,and the mixture was heated under reflux at 150 C. for one hour. Themixture was .then extracted with benezene, the extract dried over CaClaand the benzene evaporated off. 2.2 parts of the residual sulfonylchloride was reacted at a temperature of from 150 to 160 C. with 0.7part of triethylenetetramine for a period of two hours to yield areaction product effective as an antifoaming agent.

Example 4.20 parts of mahogany soap was mixed with 50 parts of PC15 andheated under reflux at 150 C. for one hour. The reaction product wasextracted with hot benzene and the benzene solution filtered. Theextract was washed with cold Water and the benzene layer dried overCaClz, filtered and evaporated. To 16 parts of the .residue was added 3parts of triethylene-tetramine. The mixture was stirred and heated at150 to 160 C. for three hours. The material .obtained as a result ofthis reaction was an antifoaming material.

Example 5.-648 parts of cetyl sulfonyl chloride and 88.5 parts ofethylenediamine (68%) were heated at 150 C. for three hours. Thereaction product was effective to reduce foaming in a steam boiler inwhich the water contained large quantities of dissolved solids.

Example 61-648 parts of cetyl sulfonyl chloride and 184.1 parts ofbenzidine were mixed and heated at 150 to.160 C.-for three hours withcasional stirring. The product was effective as an antifoaming agent.

The dicetyl sulfonamide of -o-phenylene diamine was prepared under thesame reaction conditions and formed an effective antifoaming agent. I

Example 7.648 parts of cetyl sulfonyl chloride and 104 parts ofhydroxy-ethyl-ethylenediamine were heated for three hours at 150 to 160C. with occasional stirring. The-.reaction-product was an efiectiveantifoaming agent. I

Example 8.-50 parts of cetyl sulfonyl chloride was mixed with amolecular excess of NH4OH and the mixture was warmed to insure formationof cetyl sulfonamide. This sulfonamide was mixed with a molecular excessof formaldehyde and heated for two hours at 150 to 160 C. The resultingproduct was a highly effective antifoaming agent.

Example 9.--30 parts of cetyl sulfonyl chloride were mixed with amolecular excess of ethylenediamine, and the mixture was heated at 150to 160 C. After anhour, a molecular excess of acetyl chloride was added,and heating was continued at the same temperature for an additional hourto insure complete reaction. The resulting product was a valuableantifoaming agent.

Example 10.-Molecular equivalents of hydrazine and cetyl sulfonylchloride were mixed and heated with stirring at 150 to 160 C. for threehours. To the monocetyl sulfonyl hydrazine so formed, a molecularequivalent of dichloroacetone was added, and the mixture heated for 30minutes at a temperature of 150 C. to effect a coupling reaction. Thereaction product had antifoaming properties. 1

Example 11 .-34 parts of diethylenetriamine were mixed with 108 parts ofcetyl sulfonyl chloride and 59 parts of benzene sulfonyl chloride. Themixture was heated at150 to 160 C. with stirring for three hours, andthe reaction product produced was an antifoaming agent.

Example 12.--200 parts of the detergent compound known as GeneralAniline & Film Corp. S. A. 151 was acidified with sulfonic acid andextracted with ether. The ether extract was washed and dried over CaClz,and the ether was then evaporated. 30 parts of the acid so obtained werereacted with 8 parts of SOClz in a vessel fitted with a refluxcondenser, the SOClz being added over a period of 28 minutes while thecontainer was held at 80 to 90 C., and then held at this point for twohours under continuous stirring. The reflux condenser was then removedand the contents of the container stirred at 150 C. to drive off anyexcess SOClz. 20 parts of the sulfonyl chloride so obtained was mixedwith 2 parts of diethylenetriamine and the mixture heated with stirringat 150 to 160 C. for three hours. The reaction product was eiTective asan antifoaming agent.

Example 13.5.5 parts of chlorosulfonic acid were added to 14 parts ofoleic acid and the mixture was heated at 150 to 160 C. for 30 minutes. 6parts of diethylenetriamine were then added and the mixture then heatedat 150 to 160 C. for three hours, with stirring. The resultingcomposition was an effective antifoaming agent.

The products hereinabove described, while not ordinarily regarded asappreciably soluble in water, can be dispersed in water or emulsifiedtherein by known methods so that effective amounts thereof can beintroduced and be present in the water within the liquid to preventfoaming under operating conditions. The emulsifying or dispersing agentused must, however, be of a kind 76 that doesnot'cause foaming either byitself; why its decomposition products. The compounds may be used conjointly with each other,.as well as with other known antifoaming agents,*for :example, castor oil.

The amounts of these sulfonamides which are required are extremelysmall, and in general one grain per gallon is ample. For many purposes,however, amounts of as little as grain per gallon in the feedwaterintroduced into a boiler will give valuableresults The amounts maybeeven further reduced; for example, where the feed water contains /100grain per gallon of a typical boiler water which contains solids whichwould cause foaming, foaming will be suppressed during evaporation ofsteam in the boiler for a period from 15 to 20 minutes. As contrastedwith this, where castor oil is incorporated with feed water in amountsof the order of /10 grain per gallon, thelboiler will produce foamwithin 30 seconds to one minute. Accordingly, it is obvious that if onewere to use castor oil, it would have to be injected into the boilercontinuously, and there would unavoidably accumulate in theboiler'quantitles of soap produced by the reaction of the liberatedfatty acids with the alkali present in the water, which would aggravatethe tendency to foaming. The sulfonamide compounds of the presentinvention, however, are quite stable and do not yield undesirableby-products. i

Acomparison of the operation of castor oil with the operation of thematerial described above in Example 1 showed that while 380 parts-perbillion of castor oil in the feed water permitted a maximum increase ofdissolved solids inthe boiler water from 154 to 237 grains per gallonbefore development of foaming, a dosage of 128 parts per billion'of thematerial of Exampl 1 permitted the dissolved solids in the boiler waterto rise to 870 grains per gallon without excessive foaming, priming, orcarry-over. Depending, of

course, upon the degree of concentration of solids, the dosage may bevaried, but one grain per gallon in the feed water is about as much aswould ever have to be used even under serious conditions, and for manypurposes /100 grain per gallon, and even less, can be used. The processis particularly effective in the prevention of foaming at pressures ofabout 250 lbs. .per square inch, as well as at pressures lower andhigher. These materials are efiective in boilers over a wide range ofpressure up to and over 1000 pounds per square inch.

The introduction of the antifoaming compounds of the present inventioninto the boiler may be accomplished in a number of ways. Thus, theantifoaming compositions may be dispersed or physically mixed with, say,sodium carbonate or some other material used for treating the boilerwater and pumped with the feed water into the boiler by means of eitheran injector or a feed water pump. The compounds may also be dissolved insuitable organic water-miscible solvents such as alcohols, ethers,ketones, etc., and introduced in small measured amounts into the feedwater entering the boiler. Suitable mechanical measuring devices whichwill periodically or continuously inject the required dosage of theantifoaming compounds into the feed water may be used, so that theintroduction will be more or less in proportion to the steam output towhich the steam generator is subjected. Another manner of introducingthe antifoaming compounds is to form an emulsion thereof in water andthen feed said emulsion either directly into the boiler or the feedwater lines leading to it. While the 7 operating under "invention hasbeen described in'rits useto prevent foaming "in the steam boilers, ithas been .found also to be applicable to the general suppression offoaming in other liquids such as may be used in the production of sodiumaluminate;

paper manufacture to suppress foam in the beaters or in the machine,chests, etc.; and in the manufacture or utilization of adhesives, etc.

The invention therefore is not to belimite-d by the manner ofintroduction of the antifoaming composition or to the treatment ofboiler water, but rather is to be construed in the terms of the hereuntoappended claims.

I claim:

1. Process of minimizing the production of,

foam 'in and the priming of steam generators superatmospheric pressureswhich comprises incorporating with a water therein containing an amountof total solids tend- .ing to produce foaming and priming, a quantity ofa disulfonamide of a straight chain alkyl sulfonic acid containing morethan 11 carbon atoms and a polyamine in sufficient amount tosubstantially inhibit priming and foaming, said sulfonamide not beingappreciably soluble in Water but capable of being dispersed in waterand. being substantially nonvolatile with steam.

2. Process of minimizing the production of foam in and the priming ofsteam generators operating under superatmospheric pressures whichcomprises incorporating with a water therein containing an amount oftotal solids tending to produce foaming and priming, a'quantity of adicetyl sulfonamide of diethylenetriamine sufficient to substantiallyinhibit priming and foaming.

3. Process of minimizing the production of foam in and the priming ofsteam generators operating under superatmospheric pressures whichcomprises incorporating with a water therein containing an amount oftotal solids tendingto produce foaming and priming, a quantity of adilauryl sulfonamide of triethylenetetramine sufficient to substantiallyinhibit priming and foaming.

4. Process of minimizing the production of foam inand the priming ofsteam generators op-,

eratingunder superatmospheric pressures which comprises incorporatingwith a water therein containing an amount of total solids tending toproduce foaming and priming, a quantity of a dicetyl sulfonamide ofethylenediamine ufiicient to substantially inhibit priming and foaming.

5. A process of minimizing the production of foam inand the priming ofsteam generators op erating under superatmospheric pressures whichcomprises incorporating with a water therein containing an amount oftotal solids tending to produce foaming and priming, a quantity of adisulf-onamide of a straight chain alkyl sulfonic acid containing morethan 11 carbon-atoms and a polyalkylene polyamine in sufficient amountto substantially inhibit priming and foaming, said sulfonamide not beingappreciably soluble in water but capable of being dispersed in water andbeing substantially non-volatile with steam.

ROBERT W. KELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,892,857 Spellmeyer Jan. 3, 19332,328,551 Gunderson Sept. '7, 1943 2,344,321 Orthner et a1. Mar. 14,1944 OTHER REFERENCES Monsanto Chemicals. 26th ed., 1942,, page 47.

